Selective direction television and high-frequency antenna system



pt 1952 M. P. MIDDLEMARK SELECTIVE DIRECTION TELEVISION AND HIGH-FREQUENCY ANTENNA SYSTEM Filed April 11 1952 RTTORNEY Patented Sept. 2, 1952 UNITED STATES PATENT OFFICE SELECTIVE DIRECTIGN TELEVISION AND HIGH-FREQUENCY ANTENNA SYSTEMT Marvin P. Middlemarh, Woodside, N. Y.

Application April 11, 1952, Serial No. 281,737

2 Claims. (01. 250-=33.51)

This invention relates to high frequency antennae as particularly used with television or other high frequency systems employing selective, directive radiation.

The present application is a continuation in part of my application Serial No. 241,959, filed August 15, 1951. In that prior application, I disclosed an antenna having a plurality of variously directed dipole elements, combinations of which were selectable by a selector switch to achieve directivity of reception. The instant application has the same general objectives as set forth in the above mentioned prior application, but specifically it discloses a system which is more versatile in that it provides for the selection of different directions in a much more effective and simple manner than has heretofore been provided while em ploying a switch having sixteen switch positions for this purpose. The antenna system of the instant invention operates largely by selecting one dipole rod of a series of four, and combining, by shorting, either two or three of the remaining dipole rods in different combinations. The one selected dipole rod is utilized as one element of the antenna and the shorted, remaining dipole rods are utilized as the other element. The different combinations achievevarious direction patterns of reception or transmission as will be pointed out hereinafter. I

A still further and marked advantage of the system of the instant application is the pronounced simplicity of the switch which is operated to select the various directions. The instant switch further employs only four stationary clips on one face and five on the other face thereof which clips are connected to the respective dipole elements. An output clip on each face is also provided. The rotors are so formed as to minimize the required number of clips, the results being accomplished by interconnecting two of the five clips on one face of one of the plates, and connecting the clips on the respective faces backtobacl;. Reference is here made to my Patent No. 2,585,670 which embodied the same general objectives but which employed nine switch positions instead of sixteen. The instant switch is believed to be even more versatile in selecting various directions and is further believed to be of more economical construction.

The result of reducing the number of clips while particularly forming the rotors is to decrease considerably the cost of the switch. Substantially, no soldering operations are required other than a single jumper Wire between two of the clips as will hereinafter be made clear.

The invention will be further understood from the following description and drawings in which:

Figure l is a top view of an antenna system constructed according to the instant inv ntion,

both the dipole and switch elements being shown schematic ally Figure 2 is a cross-sectional View of the selector switch; and

Figure 3 is a front view thereof.

Referring to Figure 1, the antenna elements are shown as being disposed in a horizontal plane as is customary, although the disposition of the elements for the reception of vertically polarized waves will be evident to those skilled in the art. The dipole rods H], H, I2 and ii! are shown schematically in that no supporting brackets, mast or a cross-beam are shown. However, it will be understood that the supporting bracket, crossbeam and mast may follow the form shown in my above mentioned patent or any other conventional form. t

It will be further understood that dipole rods i l and It may be considered as the two elements of a straight dipole whereas rods iii and 12 are the elements of a scond dipole, both of these dipoles being crossed. Accordingly, each dipole rod has an inner terminal end, such terminal ends being designated Isa, Ila, l2a and IE0: respectively. It is to such inner terminal ends that the transmission wire-s l4, 15, It and I l are respectively connected. As set forth in my above mentioned patent, the wires I4 to i! may be the conductors of a pair of twin transmission lines although other conventional transmission lines may be employed such as one with four conductors.

In achieving the directivity accomplished by the apparatus of the instant invention, a switch 2G is employed. Switch 28 may be disposed within or adjacentto the television equipment cabinet, probably depending upon whether it constitutes original equipment or is subsequently secured. It is manually operated by the user of the television apparatus in order to select any desired direction and thus secure the best reception.

Switch 20 is of the type referred to as a flat, wafer switch of so-called staked construction. For example, switches of this type are manuiactured by Centralab of Milwaukee, Wisconsin, and Oak Mfg. Co. of Chicago, Illinois, and are standard in the art.

As illustrated, in Figures 2 and 3, the switch includes a housing 2! having ears 22 and 23 which facilitate its connection to a support which may be the television receiver cabinet or the like. A shaft 25 having a knob operates the rotors co and their contacts. A threaded bushing 26 surrounds the shaft and a nut 27 thereon serves to secure the shaft in respect to the housing 2 I. A frame 28 is mounted on abushing 29 which is in turn secured to bushing 23. Bushings 2t and 29 are fixed relative to housings! and do not rotate with shaft 24. A toothed wheel 35) is secured to frame 28 so as to be immovable therewith. A

spring disc 3| having a tooth 32 is employed to fix the position of the shaft at the definite points, the tooth meeting with any one of the teeth of wheel 30 for this purpose.

Frame 28 includes a pair of arms which are riveted to stationary, flat, insulator ring 35. Ring 35 carries a plurality of clips to which connections are made. In the instant embodiment, such clips are disposed on both faces of ring 35. These faces are illustrated as side by sidein Figure 1 although it will be understood that they are the opposite faces of the same ring 35. In Figure 1, one face is designated as X while the other face is designated as Y. It is to be understood that no claim is made to the general construction of the switch since such construction is broadly known and conventional in the industry.

In the preferred embodiment disclosed herein, the X face of ring 35 carries five input clips designated as 40 to 44. The X face also carries an output clip designated as 45. The output clip 45 is slightly longer than the input clips so that it makes contact with the annular rotor 50 rather than with the rotor contacts and 52 which are integral with the rotor 50 and which are contacted by the input clips 46 to 44. The switch also includes a rotor plate 36 which carries the rotor and rotor contacts. Rotor plate 36 is fixed to the shaft 24 so as to rotate therewith. Plate 36, for purposes of clarity, may also be considered to have an X face and a Y face to correspond with the opposite faces of ring 35.

Referring to the switch action, the positions thereof are indexed degrees apart as illustrated in Figure 3, so that the knob 25 may travel through 240 degrees in switching through the sixteen positions. In the first preset position, rotor contact 5| is set half way past the physical extent of clip 48 as illustrated in Figure 1. Rotor contact 5| is 15 degrees wide just as are the distances between the switch position settings. The switch positions are represented by lines 31 which are central of, or bisect the stationary clips except, of course, where no clips are present. This feature is illustrated by the broken lines of Figure 3 indicating the positions of the clips relative to the switch positions. In every case where a rotor contact meets a clip, the edge of the contact is offset 7 /2 degrees therefrom as illustrated in Figure 1, the clips being 15 degrees wide.

Clips 45 and 44 are connected by a jumper wire 55, the wire |4 being connected to clip 40 so that it is also effectively connected to clip 44. The three wires |5, l6 and H are respectively connected to the clips 4|, 42 and 43 so that in all, four input wires are connected to the switch.

On the Y face of the plate there are disposed input clips 60 to 63 which are respectively connected, back-to-back, to the clips 40-43 so that the wires |4-|'| are effectively connected thereto as indicated by the broken lines of Figure 1. Such back-to-b-ack connection may be accomplished by the rivets 54.

The output clip 68 of face Y is longer than the input clips so that it effects contact with the annular rotor 69. Rotor 69 is disposed on the rotor plate 35 and is formed with a plurality of contacts, such contacts comprising a relatively Wide contact 7|], an intermediate contact H and three narrow contacts 12, I3 and I4. Output wire 15 of face Y is connected to the input of the television receiver while the output wire|6 of the face X serves as the other wire to the in put terminal of the television receiver. The Y rotor contacts are 15 degrees wide in are or are multiples thereof. Thus, contacts 12, 13 and 14 are 15 degrees wide, contact H is 30 degrees wide and contact 10 is 60 degrees wide. However, contacts 1| and 14 may be integral, or without a space between them so as to form a contact of 60 degrees. Such formation operates exactly as that which is illustrated.

Referring to Figure 3, the face of the housing 2| bears indicia representing the sixteen switch positions above mentioned, such switch positions being selected by manually rotating the knob 25.

It will be found that particular disposition of the clips and formation of the rotors, make possible the effective'selection of at least sixteen different positions covering substantially every direction with a selectable variety of lobe patterns. Thus, in the position illustrated in Figure 1, clip 40' is contacted by rotor contact 5| so that contact is effectively made with dipole rod |0 through jumper wire 55 and wire l4. At the same time, wide rotor contact 10 of face Y, makes contact with clips 6|, 62 and 63 so that wires |5, I6 and H are effectively connected to rotor 69 and to Wire 15. Accordingly, wire 15 of face X connects dipole rod In to one input terminal of the television receiver while .wire 15 of face Y connects the three remaining dipole rods to the other input terminal of the television receiver. This will produce a reception pattern in the general direction of the arrow as well as in the direction of arrow 8|. It will be recognized that the directivity indicated by arrow 80 is achieved through the conical disposition of rods I0 and II while the direction 8| is achieved by the dipole rods l0 and |3. This condition may represent position No. 1 of the indicia on the front plate of the switch housing.

In position No. 2, rotor contact 5| makes contact with clip 4|. Clip 4| is connected by wire l5 to dipole rod Thus, output wire 16 connects dipole rod H to one input terminal of the receiver. 0n the other hand, rotor contact 15 moves upward one position from that illustrated in Figure 1 so that it effects contact with clips 82 and 53. Such clips are connected through wires l6 and H to the dipole rods l2 and |3. This achieves directivity in the direction of arrow 82 as well as in the direction of arrow 83.

It will be noted that in both of the switch positions above mentioned, the wide contact 10 has the effect of shorting those dipoles which it connects to the input of the television receiver. In other words, in the first position, dipoles l2 and |3 are shorted and in the second position, dipoles I2 and I3 are shorted.

In position No. 3, the X rotor contact 5| although having moved 15 degrees, still makes contact with clip 4| which, through wire |5 makes contact with dipole The Y rotor contact 15 makes contact with clips 62 and 63 and the smaller contact 12 makes contact with clip 60. Thus, rod II is connected to one input terminal of the receiver while the remaining elements It,

I2 and 3 are connected by the Y rotor contact to the other terminal of the receiver. This accomplishes directivity in the direction of arrow 64 which is in'substantially the same direction as arrow 83 but with a different lobe pattern because difierent elements are combined to produce such directivity. It will be recognized that the directivity indicated by arrow 83 is achieved by the dipole rods H and I2 acting as a forwardly inclined dipole. Position 3 also achieves directivity in the direction of arrow 85 which substantially duplicates that of arrow 88. Th direction indicated by arrow 85 is achieved by the dipole rods and II also acting as a forwardly inclined dipole.

In position No. 4 the X rotor 50 moves up another position until the rotor contact 51 makes contact with clip 42. The Y rotor 69 is simultaneously rotated and its rotor contact 70 now only makes contact with clip 63. However, the rotor contact 72 still makes contact with clip 69. Thus, the X rotor efiectively selects dipole rod 12 while the Y rotor selects and shorts dipole rods 10 and 13. This achieves directivity in the directions of arrows 86 and 81.

In position No. 5, the X rotor 50 moves up another position but rotor contact 5| still makes contact with clip 42. Y rotor contact In still makes contact with clip 63 but rotor contact 72 makes contact with clip 6|. Thus, the X rotor selects dipole rod 12 while the Y rotor selects dipole rods II and 13. This achieves directivity in the direction of arrows 88 and 89.

In order that all 16 switch positions may be graphically set forth, the following table will indicate every position of the X and Y contacts and the directivity achieved thereby.

X Rotor Y Rotor Pos. X Contact Y Contact Dnection 1O 51 11, 12, 13 70 80, 81 11 51 12, 13 7O 82. 83 11 51 10, 12, 13 70, 72 84, 85 12 51 10.13 70.72 86, 87 12 51 11, 13 70. 72 88, S9 13 51 10, ll 72, 73 90, 91 13 51 10, 12 72, 73 92, 93 10 51 11, 12 72. 73 94, 95 10 51 11, 13 72, 73 96, 97 10 51 12, 13 72, 73 98, 09 11 52 10,12 73, 74 100, 101 ll 52 10, 13 73. 74 102, 103 12 52 10, 11, 13 71, 73, 74. 104,105 12 52 10, 11 71, 74 106, 107 13 52 10, ll, 12 71, 74 108, 109 13 52 11, 12 71, 74 110, 111

Referring to the foregoing table, it will be noted, for example, that in position 5 the X rotor selects dipole rod 12, employing the rotor contact 5| for this purpose. The Y rotor selects dipole rods 11 and I3, employing the rotor contacts 10 and 12 for this purpose. The directions accomplished by this switch position is indicated by arrows 88 and 89 as above described.

It will be observed that the arrows generally indicate eight selective directions with a plurality of arrows in each direction. Actually the arrows in any one group do not necessarily duplicate each others functions but the directions are accomplished with different lobe patterns because different elements are employed. Thus, depending upon the location of a transmitting station in any one selector, a switch position which comprises one arrow of a group of either two or six, may produce better results than one comprising a difierent arrow although in the same general direction.

It will be understood that the antenna elements may take various conventional forms and may be staked as is customary, as described and illustrated in my above mentioned prior patent.

The switch accomplishes its varied objectives with a minimum of production expenses largely because of the interconnection of the respective clips of the X and Y faces and the particular disposition of the rotor contacts on the rotors which function as selector members. It will be recognized that the rotor contacts are easily produced by stamping out rotors with the required contacts thereon. This eliminates such subsequent soldering operations as would be required if more clips were used in addition to those illustrated. In respect to the contacts noted in the table, it will be understood that contacts H and 14 may be integral as above stated.

As regards the dipole rods, these may assume conventional forms such as folded dipoles or two or more dipoles fanned out and connected to function as one dipole explained in my above mentioned prior patent.

It will be observed that the X rotor selects any one dipole rod of the four while the Y rotor selects a plurality, comprising any two or all of the remaining dipole rods. The Y rotor simultaneously shorts the selected dipole rods together to achieve the various combination described. When two dipole rods are thus shorted, the remaining rod may function as a parasitic reflector or may serve other functions. It will be further understood that the directivity indicated by the arrows in Figure 1 is general, or approximate and is not to be considered as exact as illustrated as will be evident to those skilled in the art.

What is claimed is:

1. For use with a television antenna system having a pair of crossed dipoles each consisting of two dipole rods each having an inner terminal end so that said system has four such inner terminal ends, a switch for selecting combinations of said dipole rods for connection to the input of a television receiver, said switch comprising two output terminals adapted for connection to the antenna input terminals of the receiver, two series of terminal clips in said switch, the clips of each series being respectively connected to the four inner terminal ends, and rotor means acting on both of said series of clips for electrically connecting one dipole rod to one of said switch output terminals by connecting the corresponding terminal end thereto and simultaneously and automatically shorting the three remaining terminal ends and connecting them to the other output terminal.

2. For use with a television antenna system having dipole rods extending in different directions, each of said rods having an inner terminal end, a switch for selecting combinations of said dipole rods for connection to a television receiver, said switch comprising stationary terminal members and rotatable rotor contacts for effecting electrical connection therewith, means for rotating said rotor contacts so as to provide a plurality of rest positions thereof and so that said rotor contacts effect electrical connection with said terminal members at predetermined rest positions, the outer edges of said rotor contacts effecting electrical connection with all of said terminals in offset relation thereto, each of said rotor contacts being a whole multiple of 15 in width, said terminal members all being 15 in width, and said rest positions being equally spaced 15 apart.

MARVIN P. MIDDLEMARK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,424,365 Loftin et a1. Aug. 1, 1922 2,128,279 Allison Aug. 30, 1938 2,186,949 Allison et a1 Jan. 16, 1940 2,368,286 Carlson Jan. 30, 1945 2,416,972 Williams, Jr. et a1. Mar. 4, 1947 

